1. Field of the Invention
This invention relates to an apparatus for converting the power of a reciprocating member to a unidirectional rotational motion for use as a power source.
2. Description of the Prior Art
Prior art devices have for the most part involved the conversion of transitory movement into intermittent and usually oscillating, rotational movement, and have not taught a reliable, unidirectional rotational movement of a shaft as driven by a reciprocating member. Some prior art mechanisms have used crank shafts to avoid direct conversion from a reciprocating power source, an example of which is the conventional internal combustion engine where reciprocating pistons are linked to a cam shaft to achieve rotational output.
One method of achieving rotational movement of a shaft by the use of a reciprocating source is where a cable is wrapped around a series of arbors, in the manner of warping, to convert reciprocating movement to rotational torque. In this process, a cable wrapped about a capstan or a windless transmits rotational movement by a linear displacement of the cable. Although this type of linkage demonstrates the principle of converting reciprocating movement to rotational movement, it finds limited use because of the inherent limitations of large frictional losses and arbor wear. It also introduces the variables of arbor inertia and surface smoothness. However, mechanisms using this principle have found utility in low torque devices, such as in early sewing machines and toys. Such prior art teachings relating to conversion of reciprocating motion are generally limited to those uses requiring low torque and low rotational speed.
There is a need for an apparatus that will convert reciprocating movement to rotational movement efficiently at rotational speeds that can be utilized in high torque, high speed applications. Such an apparatus must be reliable and continuous, and it must be capable of precision control. Many advantages that are to be gained from such an apparatus include savings in space brought about by the compactness of the power plant. Another advantage would be that the manufacture of expensive, precision-balanced crank shafts could be eliminated, thereby making less expensive power transfer available. An apparatus using such a power plant would find many uses at the interfaces of reciprocating power plants that drive mechanisms requiring rotational input.
One of the advantages that an apparatus such as is taught in the present invention is the achievement of constant torque for a given pressure of force of application, something that is not achieved by any other power converter. For example, on a piston drive crank shaft, the torque varies cyclically as the shaft is turned. Aside from the fact that pressure varies, the force on the crank shaft is met with varying movement effect as the crank shaft rotates. This can be avoided by a direct conversion of reciprocating power to rotational power.
A use envisioned for an apparatus converting reciprocating movement to rotational movement is in the propulsion of vehicles, as for example, in the propulsion of cycles. Prior art devices have dealt with this problem, but suggested designs have been usable as toys. The present invention discloses a precision, high quality cycle power plant, one capable of competing with modern cycle technology. An efficient cycle propelled by human effort is finding increasing need in this country as we face increasing energy conservation and pollution problems.